I need to build one that can be used outdoors.

Where can I find the schematics for this kind of circuits?

For clarification

I need to assemble a few random sound generators that can act as a sort of electronic scarecrows, but with enough capability to be able to produce sounds like footsteps, short whistles and other human common sounds.

There is no need for high definition or very wide range, as the circuits are to be placed outdoors, in a plot of land I own, and having more scattered throughout the area will be more effective than just having one or two sound sources that can be easily pinpointed.

The place is often broken into by dogs that have destroyed crops and even killed animals. These are dogs that avoid/flee from human beings and I want to use that to deincentivize them go to the place.

Ideally, these circuits are to have the smallest footprint possible, in order to be capable of being powered by a 9V battery or perhaps a small lithium rechargeable.

  • flatbield@beehaw.orgEnglish
    1·
    1 year ago

    Power supply, speaker, case, and however you want to trigger, generate, and terminate the sound. For simple sound, and oscillator circuit and specific logic. More complex they use to sell sound chips. These days you could use a raspberry pi or even an old cell phone and program it. There is probably even off the shelf stuff you could link with Wi-Fi, z-wave, or zigbee these days.

      • flatbield@beehaw.orgEnglish
        1·
        1 year ago

        Keep in mind z-wave and zigbee devices can be low power. Plus they form a mesh network so can have fairly large total area. The controller though might not be that low power.

        Dogs … they may be leaving based in small not sound. Also sound… the higher energy part of that is the actual speaker. Other the thing to think about too. Ultrasound beyond human hearing. Dogs do not like.

        The other question is how do you plan on triggering the sound. That seems a bit more complex unless it is just timer based or you pushing a button.

          • flatbield@beehaw.orgEnglish
            1·
            1 year ago

            OK. So I think you have your answer. Case, board, battery, timer circuit, tone generator. Look these up on the web. Lot of them will be based on the 555 timer chip. A common electronics store is Jameco and Newark. There are other sound chips too but I am not familiar with the numbers. Simple oscillators do not actually need an IC, could probably just be discrete. Keep in mind to electronics do have temperature ranges, performance of whatever you design will have to be tested at different temperatures.

            More realistic sounds, I think that gets harder fast. To do that you’d have to in the end record sounds into a PROM and read it out though a DtoA. Or use an SBC and program it.